The present invention is generally directed to toner and developer compositions, and more specifically, the present invention is directed to toner compositions containing on the surface thereof blend compatibility components, such as charge enhancing additives, to provide colored toners with improved blending or comixing characteristics. In embodiments, there are provided in accordance with the present invention processes to achieve effective toner blending or comixing compatibility, that is for example the overlapping of charge spectra and rapid blend admixing of the constituents in a blend of dry toner compositions comprised of resin particles, pigment particles, and optional charge additives dispersed therein, such as quaternary ammonium hydrogen bisulfates, including distearyl methyl hydrogen ammonium bisulfate, and the like by adding to the toner surfaces blend compatibility components. Thus, in embodiments with the present invention there can be obtained a palette, that is for example 10 reselected colored toners, or an extended set of colors by admixing certain toner compositions. One object of mixing or blending is to enable a minimum starting set of toners such as red, green, blue, cyan, magenta and yellow to generate many other colors by the method of comixing these toners, pairwise in embodiments, to provide toners with preselected colors, thus each new comixture, with a relative ratio of the constituent pair, can become a new toner to be added to a carrier to form a developer particularly useful in trilevel or color xerography. The aforementioned toner compositions usually contain pigment particles comprised of, for example, carbon black, magnetites, or mixtures thereof, cyan, magenta, yellow, blue, green, red, or brown components, or mixtures thereof thereby providing for the development and generation of black and/or colored images. The toner compositions of the present invention in embodiments thereof possess excellent admix characteristics as indicated herein, and maintain their triboelectric charging characteristics for an extended number of imaging cycles, exceeding for example 500,000 in a number of embodiments. The toner and developer compositions of the present invention can be selected for electrophotographic, especially xerographic, imaging and printing processes, including full color processes.
Developer compositions with charge enhancing additives, which impart a positive charge to the toner resin, are known. Thus, for example, there is described in U.S. Pat. No. 3,893,935 the use of quaternary ammonium salts as charge control agents for electrostatic toner compositions. In this patent, there are disclosed quaternary ammonium compounds with four R substituents on the nitrogen atom, which substituents represent an aliphatic hydrocarbon group having 7 or less, and preferably about 3 to about 7 carbon atoms, including straight and branch chain aliphatic hydrocarbon atoms, and wherein X represents an anionic function including, according to this patent, a variety of conventional anionic moieties such as halides, phosphates, acetates, nitrates, benzoates, methylsulfates, perchloride, tetrafluoroborate, benzene sulfonate, and the like. Also of interest are U.S. Pat. Nos. 4,221,856, which discloses electrophotographic toners containing resin compatible quaternary ammonium compounds in which at least two R radicals are hydrocarbons having from 8 to about 22 carbon atoms, and each other R is a hydrogen or hydrocarbon radical with from 1 to about 8 carbon atoms, and A is an anion, for example sulfate, sulfonate, nitrate, borate, chlorate, and the halogens such as iodide, chloride and bromide, reference the Abstract of the Disclosure and column 3; a similar teaching is presented in U.S. Pat. No. 4,312,933, which is a division of U.S. Pat. No. 4,291,111; and similar teachings are presented in U.S. Pat. No. 4,291,112 wherein A is an anion including, for example, sulfate, sulfonate, nitrate, borate, chlorate, and the halogens. There are also described in U.S. Pat. No. 2,986,521 reversal developer compositions comprised of toner resin particles coated with finely divided colloidal silica. According to the disclosure of this patent, the development of electrostatic latent images on negatively charged surfaces is accomplished by applying a developer composition having a positively charged triboelectric relationship with respect to the colloidal silica.
Also, there are illustrated in U.S. Pat. No. 4,338,390, the disclosure of which is totally incorporated herein by reference, developer compositions containing as charge enhancing additives organic sulfate and sulfonates, which additives can impart a positive charge to the toner composition. Further, there is disclosed in U.S. Pat. No. 4,298,672, the disclosure of which is totally incorporated herein by reference, positively charged toner compositions with resin particles and pigment particles, and as charge enhancing additives alkyl pyridinium compounds. Additionally, other documents disclosing positively charged toner compositions with charge control additives include U.S. Pat. Nos. 3,944,493; 4,007,293; 4,079,014; 4,394,430, and 4,560,635, which illustrates a toner with a distearyl dimethyl ammonium methyl sulfate charge additive.
The following United States patents are also mentioned: U.S. Pat. No. 4,812,381 which discloses toners and developers containing charge control agents comprising quaternary ammonium salts of the formula indicated, for example, in the Abstract of the Disclosure, wherein R is alkyl with from 12 to 18 carbon atoms, and the anion is a trifluoromethylsulfonate; U.S. Pat. Nos. 4,834,921 and 4,490,455, which discloses toners with, for example, amine salt charge enhancing additives, reference the Abstract of the Disclosure for example, and wherein A is an anion including those derived from aromatic substituted sulfonic acids, such as benzene sulfonic acid, and the like, see column 3, beginning at line 33; Reissue 32,883 (a reissue of U.S. Pat. No. 4,338,390) illustrates toners with sulfate and sulfonate charge additives, see the Abstract of the Disclosure, wherein R.sub.4 is an alkylene, and the anion contains a R.sub.5 which is a tolyl group, or an alkyl group of from 1 to 3 carbon atoms, and n is the number 3 or 4; U.S. Pat. No. 4,323,634 which discloses toners with charge additives of the formulas presented in column 3, providing that at least one of the R's is a long chain amido group, and X is a halide ion or an organosulfur containing group; U.S. Pat. No. 4,326,019 relating to toners with long chain hydrazinium compounds, wherein the anion A can be a sulfate, sulfonate, phosphate, halides, or nitrate, see the Abstract of the Disclosure for example; U.S. Pat. No. 4,752,550 which illustrates toners with inner salt charge additives, or mixtures of charge additives, see for example column 8; U.S. Pat. No. 4,684,596 which discloses toners with charge additives of the formula provided in column 3 wherein X can be a variety of anions such as trifluoromethane sulfonate, and U.S. Pat. Nos. 4,604,338; 4,792,513; 3,893,935; 4,826,749 and 4,604,338.
Moreover, toner compositions with negative charge enhancing additives are known, reference for example U.S. Pat. Nos. 4,845,003; 4,411,974 and 4,206,064, the disclosures of which are totally incorporated herein by reference. The '974 patent discloses negatively charged toner compositions comprised of resin particles, pigment particles, and as a charge enhancing additive ortho-halo phenyl carboxylic acids. Similarly, there are disclosed in the '064 patent toner compositions with chromium, cobalt, and nickel complexes of salicylic acid as negative charge enhancing additives.
There is illustrated in U.S. Pat. No. 4,404,271 a process for developing electrostatic images with a toner which contains a metal complex represented by the formula in column 2, for example, and wherein ME can be chromium, cobalt or iron. Additionally, other patents disclosing various metal containing azo components wherein the metal can be chromium or cobalt include U.S. Pat. Nos. 2,891,939; 2,871,233; 2,891,938; 2,933,489; 4,053,462 and 4,314,937. Also, in U.S. Pat. No. 4,433,040, the disclosure of which is totally incorporated herein by reference, there are illustrated toner compositions with chromium and cobalt complexes of azo dyes as negative charge enhancing additives.
Illustrated in U.S. Pat. No. 4,937,157 (D/89260), the disclosure of which is totally incorporated herein by reference, are toner compositions comprised of resin, pigment, or dye, and tetraalkyl, wherein alkyl, for example, contains from 1 to about 30 carbon atoms, ammonium bisulfate charge enhancing additives, such as distearyl dimethyl ammonium bisulfate, tetramethyl ammonium bisulfate, tetraethyl ammonium bisulfate, tetrabutyl ammonium bisulfate, and preferably dimethyl dialkyl ammonium bisulfate compounds where the dialkyl radicals contain from about 10 to about 30 carbon atoms, and more preferably dialkyl radicals with from about 14 to about 22 carbon atoms, and the like.
The disclosures of each of the U.S. patents mentioned herein, especially as they relate to toners with charge additives, are totally incorporated herein by reference.
A number of copending applications illustrate toners with negative charge additives such as U.S. Ser. No. 755,919 (D/90404) and U.S. Ser. No. 894,688 (D/92080), the disclosures of which are totally incorporated herein by reference.